Dental tool and control apparatus



May 10, 1966 R. A. WHITE DENTAL TOOL AND CONTROL APPARATUS 2 Sheets-Sheet 1 Filed Sept. 7, 1962 INVENTOR.

Y fiAYMoND '4. 11 17/76 May 10, 1966 R. A. WHITE 3,250,005

DENTAL TOOL AND CONTROL APPARATUS Filed Sept. '7, 1962 2 Sheets-Sheet 2 R E 7 %\r\ wnm mm Q 1 w J Q AA A p. Q m 1 1 2 PM wm wk 1 N ru Y M I, B M \|M.Q\ N Z NM, om FH m3 kw \M. w R mm m Y .W .WNFPX M\ m NRN m BN mm Q km A eewr United States Patent 3,250,005 DENTAL TOOL AND CONTROL APPARATUS Raymond A. White, San Pedro, Calif, assignor to The Dentists Supply Company of New York, York, Pa., a

corporation of New York Filed Sept. 7, 1962, Ser. No. 222,122

9 Claims. (CI. 3227) v This invention relates to a dental tool control apparatus and is particularly concerned with dexterity and control of dental tools whereby manipulation of said tools is facilitated. Specifically, this invention has to do with the control of dental handpieces and the like and those handpieces which require the flowof fluids for their operation. That is, air and/ or water and air-Water mists are to be controlled and directed to dental tools such as handpieces, and all of this is to be accomplished during dental processes and without delay or inconvenience to the dentist or his patient.

Reference is made to my co-pending application Serial No. 103,293, filed April 17, 1961, entitled Dental Tool and Handpiece Control, now abandoned.

Dental procedures involve certain usual tools including drills operated by a handpiece through a separate control, retractors, mirrors, and supply means for fluid coolants including air and water and/ or mixtures thereof. It is the usual practice to separately employ these various implements, resulting in considerable use of time in transferring from one implement to the other and resulting in interim periods when no action is being performed. That is, usual dental tools and implements require the dentist to process the patient by separately making the necessary observations and drilling operations consecutively, and interrupted by operations involving the removal of debris and by inspections. For example, after an initial inspection a tooth is drilled; this is followed by removal of debris; and then follows another inspection; and so on, and this sequence is repeated until .a cavity is properly prepared. It is significant that tools are exchanged for each other during these separate procedures accompanied by loss of time.

From the foregoing it should be apparent that any inconvenience or loss of time to a dentist and his patient is a detriment and that any implement or apparatus that is more convenient and such as to save time has particular utility. It is in this respect that the improvements of the present invention are directed, it being a general object of this invention to provide a most convenient control apparatus for dental handpieces and the like and a control that is operable remotely to govern the flow of fluids to said handpieces.

An object of this invention is to provide a dental control that permits full dexterity of the dentists hand in the manipulation of said tool and wherein the. said dentist has full control over a plurality of fluid delivering lines or tubes.

Another object of this invention is to provide a dental tool of the character referred to and which is particularly adapted for the prehensile grip by the hand of the dentist and further whereby fingers of the dentists hands are left remaining for dexterity and full control of at least one or a plurality of fluid controls.

It is still another object of this invention to provide a fluid controlling relay in combination with a remote fluid controlling valve and whereby the current or flow of said fluid determines the operation of said relay. Further, the said fluid relay is automatically reset when the flow of fluid is stopped.

The various objects and features of this invention will be fully understood from the following detailed description of the typical preferred form and application thereof,

"' 3,250,005 Patented May 10, 1966 throughout which description reference is made to the accompanying drawings, in which:

FIG. 1 is a perspective view showing the right and left hands of a dentist and particularly the prehensile grip of the left hand with the tool of the present invention and whereby the index finger is left free for maximum dexterity in the control of valve operating levers, and showing diagrammatically the apparatus used and associated in combination with the tool of the present invention.

FIG. 2 is an enlarged sectional view taken through the head of the handpiece shown in FIG. 1.

FIG. 3 is an enlarged detailed sectional view taken as indicated by line 33 on FIG. 1.

FIG. 4 is a fragmentary view of a portion of the structure shown in FIG. 3.

FIG. 5 is an enlarged sectional view illustrating the fluid relay shown in the diagrammatic portion of FIG. 1.

FIG. 6 is a perspective view of one of the parts as used in mounting the mirror shown in FIGS. 1 and 3.

With the control apparatus that I provide a very sure and prehensile grip is provided for in the use of the middle finger opposed to the thumb of the hand. Further, a finger of the dentists hand is completely free of dextrous use, this finger being the index finger that is strong and ordinarily considered the most controllable finger of the hand. In FIG. 1 of the drawings I have shown a perspective illustration of the prehensile grip that I refer to and which I have found to bemost convenient and which permits the free use of the index finger to actuate the control valve levers hereinafter described. Generally, the apparatus involves a handpiece X, a control implement Y, and, a fluid power supply. The handpiece X can be of any type, that is, it can be electrically operated through a direct or indirect belt drive, or as it is preferably illustrated it can be a pneumatically operated handpiece with the drive in the head portion thereof. The control implement Y is the characteristic feature and/or component of the present invention and is a dental tool in the form of a dental mirror and/ or dental retractor with control means incorporated therein to govern action of the handpiece X. The fluid power control is unique by theinclusion of a fluid relay R hereinafter described.

In the particular construction illustrated the handpiece X is of the contra angle type wherein the axis of the head is at an angle to the axis of the handpiece body. Further, the power or energy for driving the rotating elements is conducted to and from the handpiece through flexible tubings 7, 8 and 9 that are swivelly coupled to the rearunost end of the handpiece body.

The driving head of the handpiece X, as best illustrated in FIG. 2 of the drawings, is a drive unit or prime mover and involves, generally, a case 10, a shaft 11 rotatablycan ried in the case to project'from one end thereof, a stator 12 fixed in the case to receive and direct fluid handled by the driving head, and a rotor 13 preferably integral with the shaft 11 to receive fluid directed by the stator and adapted to rotate the shaft.

The case 10 is an elongate shell-like part with a coneshapedouter wall tapered inwardly toward the lower end thereof. A seat is provided at the lower end of the case 10 to carry an anti-friction bearing 14, and a shoulder is provided intermediate the ends of the case 10 to support the stator 12 in the case. Intermediate the bearing 14 and stator 12 there is an exhausting chamber 15 defined by the wall of the case 10 and surrounding the shaft 11. A cover 16 closes the top of the case 10 and has a seat to carry an anti-friction bearing 17. The bearings 14 and 17 rotatably support the shaft 11 within the case 10, the lower end of the, shaft 11 projecting somewhat from the bottom of the case.

The stator 12 receives fluid under pressure, preferably air or the like, through a port 18 in the wall of the case 10 and supplied with flow of air from the tubing 8. The stator 12 is characterized by an annular chamber defined by the wall of the case and an inner wall of the stator 12. Fluid received by the stator 12 is directed upwardly through vanes that are carried thereby, said vanes being in a continuous annular series.

The rotor 13 receives fluid directed upwardly by the stator 12 and is adapted to handle the fluid so that it is conducted inwardly and downwardly, imparting driving force to the rotor 13. The rotor 13 is preferably integral with the shaft 11 and has a continuous annular series of blades. The stator vanes and blades are suitably pitched, in the direction of rotation, and as circumstances require, in order to gain the desired speed of rotation, etc.

The head is employed to drive a cutter K, for example, a burr cutter, as shown. The shaft 11 has a straight bore 22 entering the lower end thereof to slidably receive the shank 23 of the cutter. The upper end of the cutter shank 23 is notched to engage with a key in the bore 22. In order to retain the cutter K in working position, I may provide a friction exerting or detent-type collet at the lower end portion of the shaft 11. For example, the lower end portion of the shaft 11 is split at and provided with inward projections that engage in a groove in the shank 23.

In operation, fluid used to drive the rotor is received from the lower end of the rotor by the exhausting chamber 15, and it is directed from the chamber through an enlarged exhaust port in the side wall of the case 10 (see FIG. 2), and it is finally directed to exhaust through the tubing 7. It will be apparent that the dental tool or handpiece X thus far described is adapted to be conveniently manipulated by one hand of the dentist,'preferably the right hand, as shown.

The control for the handpiece X is incorporated in the control implement Y which additionally serves a plurality of functions, namely as a dental mirror for inspection as work progresses, as a retractor to hold back and position facial tissues, and as a fluid or coolant applicator. In accordance with the invention the control implement Y involves, generally, a body A having a prehensile grip, valve means V and V, fluid coupling means B, control means C and C, and a fluid or coolant applicating implement E having a replaceable mirror M on a removable stem 30.

The body A is to be considered the stationary element of the structure with a part at the forwardmost portion thereof to be gripped between the thumb and middle finger of the hand, and with the structure to be herinafter described in connection with the two valve means V and V there are parts at opposite ends of the body that are movable axially and adapted to variably control flow of fluid. air, from the power supply later described. The control means C and C are adapted to be manipulated by the index finger of the dentist at the one hand of said dentist that is used to carry and position the control implement Y, preferably the left hand as shown.

The coolant applicating implement directs flow of fluid in the direction of the work being performed and upon the face of the mirror M which forms a part thereof, to defog the same. And, the fluid coupling means B directs air to and from the control implement Y and through the implement Y, whereby separate and selectively variable flows of air are conducted to the handpiece X and fluid or coolant applicating implement E respectively.

The body A is an elongate tubular element that carries the parts comprising a handle to be gripped and manipulated by the dentists hand, and which more specifically carries the fulcrum for the levers of the control means C and C', and carries the fixed seats of the valve means V and V, all as described in connection with said means respectively. Generally, the body A comprises a tubular element with two oppositely faced enlargements 37 and 38 spaced therealong and rearward of a grip sleeve 39. Thus, the body A is characterized by a cylindrical or tubular part having spaced enlargements 37 and 38 and 4, with a central bore 34 that extends through the body. Further, the body involves an extension 32 that projects forwardly from or within an operator 0 for the valve V' and an extension 33 that projects rearwardly from therearmost enlargement 37 for carrying the valve V. The extensions 32 and 33 have threaded end portionsto receive spring seats 35 and 36. It will be apparent that the body A can be readily machined as a simple turned part.

The prehensile grip sleeve 39 is caried'by the operator 0 that is rotatable on the body A and is provided for being gripped between the thumb and middle finger of the hand, and for this reason it is located at the forwardmost end of the body A. Operator 0 is a spool-shaped part slidable on the body to be pressed into engagement with a valve controlling part as later described. As a result of said forward position of the grip sleeve 39, the index finger is left free for the manipulation of the control means C and C. It will be apparent that different persons will have hands and fingers of different form and/or size and will have developed differences in their manipulation abilities. Therefore, the grip sleeve 39 is axially adjustable and is adjustably movable and locked in the desired selected position by a nut 39. The exterior of both the sleeve 39 and nut 39 is knurled for the usual and obvious reasons, and said sleeve 39 and nut 39 are provided in pairs whereby the most desirable diameter thereof can be selected in order to best suit the person who is to handle and manipulate the tool Y. It will be apparent that a most convenient diameter of grip elements can be selected and that they are adjustable as circumstances require.

The coupler B is an extension of the body A and projects rearwardly for communication with tubings 40 and 4 1. In practice, it is desirable to have a swivel connection between all of the body parts, in which case the coupler B is swivelly projected from the rear of the body A. That is, the projecting coupler B is rotatable on the axis of the body A, having a central bore 42 slidable longitudinally and rotatable on the extension 33 at the rear of the body A. The rearmost end and bottom of the bore 42 is shaped to form one of the valve elements of the valve V, said bore 42 being in open communication with a supply duct 44 as Well as with the bore 34 that extends through the body A. The duct 44 receives fluid under pressure from a laterally disposed connector 45 at the outermost end of the coupler B, and there is a second laterally disposed connector 46 forward of the bottom of said bore 42 to discharge fluid under pressure from the coupler B. Said connectors 45 and 46 are adapted to couple with the tu-bings 40 and 41, respectively.

The valve means V involves the above described coupler B that is movable longitudinally relative to the body A to reciprocate. In practice, the above mentioned sliding fit is close enough to substantially prevent leakage forwardly, thus confining fluid to the bores42 and 34. The means V involves a valve seat .47 or element of reduced diameter and in the form of a male part that projects rearwardly from the extension 33 and forming an annular chamber forwardly of the bottom of the bore 42. The movable valve element 48 that engages the seat 47 is formed in the bore 44, and engagement of element 48 with the seat 47 prevents flow of fluid to the annulus surrounding the bearing, or allows flow variably as the distance is increased between the seat 47 and element 48. As indicated, the said annulus is in constant communication with the lateral connector 46.

The control means V is a valve means disclosed and claimed in my co-pending Serial No. 67,758 entitled Valve Control for Dental Handpiece, filed November 7, 1960, now Patent No. 3,125,809, and as best illustrated in FIG. 4 0f the drawings, the valve means V involves the cooperative engagement of a valve seat element 51 with a valve element 52. However, the complexity of slidably related telescopic tubes is eliminated and replaced by a very simple of the type application and practical arrangement of parts. As shown, the valve seat element 51 is a male part incorporated in the formation of the extension 32 and which slidably enters a cylindrical bore 53 in a wall 54. And, the only other feature of construction required is the formation of a seat 55. Said seat 55 is formed at the forwardmost end face of the body A, preferably a conically tapered seat, surrounding the fluid passage 34.

The valve element 52 is a unit of construction carried by the sleeve 39 and is provided in various lengths in order to have the axial adjustment of the grip sleeve 39, as above described. That is, the said adjustment of the grip is correlated with the working adjustment of the valve element 52. The element 52 is seated forwardly in the bore 53 in wall 54 at the front sleeve 39, thereby positively positioning the valve element 52. The element 52 is lightly pressed into position and its projecting nose portion 56 of reduced diameter has a face to mate with the seat 55 to engage therewith and stop fluid flow.

Thus, there is an annular chamber surrounding the element 52. The interior of element 52 is bored out to open forwardly into a passage 58, there being a lateral port or opening 57 to communicate with the said annular chamber and through said opening 57 to said passage 58..

Therefore, removal of element 52 from the seat 55 results in the flow of fluid into passage 58. It will be apparent that a valve element 52 of suitable length can be selected in order to gain the desired axial position of the sleeve 39, and that the position of the sleeve is readily adjustable in order to gain proper seating of the valve element 52.

The control means C and C are essentially identical, the meansC being operable 'to actuate the valve means V, and the means C being operable to actuate the valve means V. As shown, each of said means involves, generally, a fulcrum F, a lever L and an operator 0. The fulcrums F are formed on the rearward extension 3-3 of the body A, and the levers L of the two said means are engaged with said respective fulcrums to operate said respective operators 0. Thus, the operator 0 of means C actuates the valve means V, while the operator 0 of means C actuates the valve means'V.

The fulcrum F may be a simple pivot, however in accordance with the preferred form of the invention, it is a circular element that extends continuously around the body A of the handpiece. As illustrated in the drawings, the fulcrum F is in the form of a ring engaged over and projecting from the outer wall of the body A, and as shown, the outer wall of the ring is curved about a radius to have bearing engagement with the lever L, as hereinafter described.

The lever L is a circular and rotatable element that surrounds the body A to be manually engageable at any point or position around the body. As illustrated, the lever L is in the form of a collar that encircles the body A with some clearance therebetween. The inner wall 76 of the collar is larger in diameter than the body A and engages over the ring that forms the fulcrum F. A flange extends inwardly at the rear end portion of the collar and is provided with a rearwardly disposed operating face 78 and with a curved annular seat that has bearing engagement with the matching curved wall of the ring. Both the said wall and the said seat are continuous annular parts that are adapted to have bearing contact with each other at any point around the structure.

By depressing the forward end portion of the collar inwardly, at any point around the circumference thereof, the flange is rocked from its normally transverse plane normal to the axis of the handpiece, so that the peripheral part thereof diametrically opposite the pivot point is moved axially rearward. It will be apparent that depression of the collar at any point will rock the flange and will cause maximum rearward motion at a point on the operating face 78 diametrically opposite the pivot point. The said operating face-78 is normally in flat engagement with the end 74 of the operator 0, and when the lever L is depressed, as above set forth, the end 74 of the operator 0 is directly engaged and shifted axially.

Each operator 0 is adjustably coupled to the valve element actuated thereby, the coupler B involving the movable seat 47 is coupled by a sleeve 81, and the valve element 52 involving valve seat 55 is coupled by the sleeve 39. The sleeve 81 is threadedly engaged with the rearmost operator 0 and secured in a selected position by a lock nut 84, there being a compression spring 85 to yieldingly urge the operator forwardly to hold the lever L in a normal unactuated position to close the valve means V.

- Further, the said sleeve 81 is swivelly coupled to the coupler B as by means of a flange on one part operating in a channel in the other part, as shown. The sleeve 39 is threadedly engaged with the forwardmost operator 0 and secured in a locked position by the lock nut 39', there being a compression-spring 87 to yieldingly urge the operator rearwardly to hold the lever L in a normal unactuated position to close the valve means V'. It will be apparent how suitable adjustment can be made at the threaded connections between the operators 0 and sleeve 81 and sleeve 39, to remove all play from the mechanism.

The fluid or coolant applicating implement E is a multipurpose device which includes a mirror M that is defogged when fluid is discharged through the implement. The implement E receives fluid, air, from the valve V and is mounted rigidly with the sleeve 39 and its wall 54, these parts of the entire device being the only major parts that do not revolve one relative to the other. Notice that all major parts are rotatable on the body A and relative to each other, with the exception of the sleeve 39 and the implement E attached thereto.

The implement E involves a tubular body 90 coupled to and projecting from the sleeve 39, a discharge nozzle 91, a tie-fogging nozzle 92, and the mirror M. The body 90 is threadedly coupled into the wall 54 to be in open communication with the passage 58. The nozzle 91 is a nut that is threaded onto the terminal end of the body 90 and which has a suitable jet opening therein for the discharge of fluid. The de-fogging nozzle 92 is a laterally opening nozzle positioned intermediate the ends of the body and with a slot-shaped jet opening therein for the discharge of a fan-shaped spray in a plane adjacent to the body 90 and substantially parallel therewith.

A feature of the implement E is the replaceability of the mirror M which is gripped between a pair of opposed spring clips 95. The clips 95 are arcuately formed so as to press onto the periphery of the mirror M which is round and there is a central opening to pass the body 90. The nozzle 92 overlies the innermost clip 95 to prevent rotation thereof, and/ or it may be brazed thereto, while the outermost clip 95 is simply pressed into position by the threaded nozzle 91. The mirror M fits against the body 90, there being hooks 96 at the ends of the clips 95 to overlie the mirror and to press it onto the body. Thus, mirrors M having variations in diameter are secured in operating position and are easily removed and/ or replaced.

In FIG. 1 of the drawings I have shown the fluid relay R that operates in combination with the control tool Y. The purpose of this relay is to provide for the control of a third fluid in addition to the two fluids hereinabove described in connection with the valve means V and V. In practice, the valve V controls fluid to the prime mover of the drilling tool X, the valve V controls coolant fluid to the implement E, and the fluid relay R is sensitive to flow of fluid in the valve V (or valve V) to control coolant fluid or the like to the drilling tool X. The purpose of this third control relay R is to start and stop coolant fluid that is delivered to the drilling handpiece X. Turbine drive air is supplied to the handpiece through tubing 8 and is exhausted through tubing 7, while a coolant of misted fluid is supplied thereto through a tubing 9 under control of the said relay R.

The fluid relay R is a cylinder and piston device having a cylindrical body 100 and a single moving piston 101. The piston 101 is freely slidable in the cylinder 100, preferably with some clearance, whereby air under pressure will bleed axially therefrom as later described. There is an inlet opening at 102 at the inlet end of the cylinder 100 and opening axially into the cylinder and tending to move the piston axially. Said axial movement of the piston is resisted by a variably tensioned spring 103 adjustable by means of a threaded thumb screw 104 that enters the opposite end of the cylinder. The spring 103 occupies a chamber 105 that receives and vents air that bleeds by the piston. The piston 101 carries a valve element 106 that is opposed to a seat 107 surrounding the opening at 102, and the structure is characterized by the substantial differential in effective areas of the piston 101 and valve 106107. The piston is much the larger.

In accordance with the invention, the piston 101 is moved by unseating element 106 utilizing the fluid pressure applied to the turbine through tubing 8. Further, the cylinder is provided with a seat 108 at the end opposite the inlet opening 102, whereby the differential effect of fluid under pressure in the cylinder 100 causes seating of the piston 101 to close off the chamber 105 and to open a line 100 to the fluid pressure source occurring in the cylinder 100. The line 109 is normally closed by the piston when seated under the influence of spring 103, and is opened by pressure overcoming said spring to force the piston onto seat 103. A suitable fluid operated valve 115 is operated by fluid under pressure in line 109, to control the supply of misted air and water as clearly indicated throughout the drawings. When the line 109 is closed, fluid in valve 115 slowly bleeds into the vented chamber 105 in order to release the valve 115, and when the piston 101 is unseated and shifted as a result of the application of more than a normal amount of fluid flow valve 115 is operated.

From the foregoing it will be apparent that I have provided an extremely versatile and convenient control apparatus for a plurality of implements and/ or tools used in the dental processes. Primarily, a dental tool in the form of an implement is manipulated surely through a prehensile grip while a plurality of controls associated therewith are conveniently located for operation by the index finger of the person handling the tool. It is to be observed that all of the major elements or parts of the said controlling tool are rotatable relative to each other, and they all swivel as circumstances require. Not only are the levers universally depressed, but they also turn as may be required during the manipulation of the dental implement E. Secondarily, in addition to the primary control of the turbine driven handpiece, a third control of fluid is provided for by means of the fluid relay R which is sensitive to more than normal flow of fluid and which can be controlled at will to start or stop the flow of coolant or fluid mist to the handpiece X. So long as a normal flow of fluid is delivered to the turbine powered driving head, then the valve 115 remains closed. In order to open valve 115 and thereby cause the flow of coolant fluid it is merely necessary to momentarily increase the fluid flow to the turbine whereupon the piston 101 is unseated from seat 107 and reseated on seat 108 to thereby cause fluid pressure to operate the valve 115 to open. Further, said piston 101 remains latched in said unseated and reseated position until fluid pressure is removed from line 8.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

1. In combination with a fluid power operated dental tool to be manipulated by one hand of the user and with a separate fluid pressure applicating connection thereto, a fluid control tool to be manipulated by the other hand of the user, there being a fluid connection extending between the two said manipulated tools to operate a first means at the first mentioned tool, a variable pressure fluid power supply in the said fluid connection extending between said tools, and a fluid power sensitive relay in communication with the fluid connection between the tools to control flow in said fluid pressure applicating connection to a second means at the said first mentioned tool.

2. In combination with a fluid power operated dental tool to be manipulated by one hand of the user and with a fluid pressure line connected thereto, a control tool to be manipulated by the other hand of the user, there being a fluid connection extending between the two said manipulated tools to operate a first means at the first mentioned tool, a variable pressure power supply in the said fluid connection extending between said tools, and a power sensitive relay in communication with the fluid connection between the tools and comprising a cylinder and piston unit operable upon abnormal supply of power to control flow in said fluid pressure line to a second means at the said first mentioned tool.

3. In combination with a fluid power operated dental tool to be manipulated by one hand of the user and with a separate fluid pressure applicating connection thereto, a fluid control tool to be manipulated by the other hand of the user, there being a fluid connection extending between the two said manipulated tools to operate a first means at the first mentioned tool, a variable pressure fluid power supply in the said fluid connection. extending between said tools, and a fluid power sensitive relay in communication with the fluid connection between the tools and comprising a cylinder and piston unit operable upon abnormal supply of fluid power to control flow in said fluid pressure applicating connection to a second means at the said first mentioned tool.

4. In combination with a fluid power operated dental tool to be manipulated by one hand of the user and with a separate fluid pressure applicating connection thereto, a fluid control tool to be manipulated by the other hand of the user, there being a fluid connection extending between the two said manipulated tools to operate a first means at the first mentioned tool, a variable pressure fluid power supply in the said fluid connection extending between said tools, and a fluid power sensitive relay in communication with the fluid connection between the tools and comprising a cylinder with an inlet at one end, a piston slidable in the cylinder and normally seated at said inlet, means to bias the piston into said seated engagement, and a lateral line normally covered by the piston and uncovered by the piston when said piston is removed from the seat to control flow in said fluid pressure applicating connection to a second means at the said first mentioned tool.

5. In combination with a fluid power operated dental tool to be manipulated by one hand of the user and with a separate fluid pressure applicating connection thereto, a fluid control tool to be manipulated by the other hand of the user, there being a fluid connection extending between the two said manipulated tools to operate a first means at the first mentioned tool, a variable pressure fluid power supply in the said fluid connection extending between said tools, and a fluid power sensitive relay in communication with the fluid connection between the tools and comprising a cylinder with an inlet at one end, a piston slidable in the cylinder and normally seated at said inlet, means to bias the piston into said seated engagement, and a lateral line normally coveredby the piston and uncovered by the piston when said piston is removed from the seat to control flow in said fluid pressure applicating connection to a second means at the said first mentioned tool and a seat opposite the first mentioned seat and larger than the first mentioned seat to hold the piston.

6. A fluid control for a dental implement comprising:

(a) a tubular body with a pair of spaced fulcrums thereon,

(b) a finger operable lever pivoted on each fulcrum,

(c) a valve at each end of the body and controlling (d) and an operator for each valve and slidable over the body between the fulcrum and said ends of the body and each adapted to be shifted to individually operate the valve by actuation of the lever.

7. A fluid control for a dental implement comprising:

(a) a tubular body with a pair of spaced fulcrums in the form of rings surrounding the body,

(b) a pair of finger operable levers and each in the form of a collar engaged-over the body and each having bearing engagement with one of said fulcrums,

(c) a valve at each end of the body and controlling fluid flow to the body,

(d) and an operator for each valve and slidable over the body between the fulcrums and said ends of the body and each adapted to be shifted to individually operate the valve by actuation of the lever.

8. A fluid control for a dental implement comprising:

(a) a tubular body with a pair of spaced fulcrums in the form of rings surrounding the body,

(-b) a pair of finger operable levers and each in the form of a collar engagedover the body and each having bearing engagement with one of said fulcrums.

(c) a valve seat at each end of the body,

(d) a pair of operators and each in the form of a sleeve slidable over the end of the body,

(e) and a valve element carried by each operator to engage one of said seats,

(f) the operators being shiftable axially to operate the valve elements relative to the seats upon movement of said levers about said fulcrums.

9. A fluid control for a dental implement comprising:

(a) a tubular body with a pair of spaced fulcrums in the form of rings surrounding the body,

(b) a pair of finger operable levers and each in the form of a collar engaged over the body and each having bearing engagement with one of said fulcrums,

(c) a valve seat at each end of the body,

((1) a pair of operators and each in the form of a sleeve rotatable and slidable over the end of the body,

(e)' and a valve element carried by each operator to engage one of said seats,

(f) the operators being shiftable axially to operate the valve elements relative to the seats upon movement of said levers about said fulcrums.

References Cited by the Examiner UNITED STATES PATENTS 918,930 4/ 1909 Thurman 251-303 932,068 8/1909 Thurman 251303 2,928,174 3/ 1960 White. 2,984,909 5/ 1961 Johnston 32-69 3,001,288 9/1961 Freedman 32-69 RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner. 

1. IN COMBINATION WITH A FLUID POWER OPERATED DENTAL TOOL TO BE MANIPULATED BY ONE HAND OF THE USER AND WITH A SEPARATE FLUID PRESSURE APPLICATING CONNECTION THERETO, A FLUID CONTROL TOOL TO BE MANIPULATED BY THE OTHER HAND OF THE USER, THERE BEING A FLUID CONNECTION EXTENDING BETWEEN THE TWO SAID MANIPULATED TOOLS TO OPERATE A FIRST MEANS AT THE FIRST MENTIONED TOOL, A VARIABLE PRESSURE FLUID POWER SUPPLY IN THE SAID FLUID CONNECTION EXTENDING BETWEEN SAID TOOLS, AND A FLUID POWER SENSITIVE RELAY IN COMMUNICATION WITH THE FLUID CONNECTION BETWEEN THE TOOL TO CONTROL FLOW IN SAID FLUID PRESSURE APPLICATING CONNECTION TO A SECOND MEANS AT THE FIRST MENTIONED TOOL. 